1. Field of the Invention
The invention relates to a bumper for an umbrella, and particularly a bumper secured on a shank of the umbrella to provide a shock-absorbing effect when the umbrella opens.
2. Description of Related Art
With reference to FIG. 4, a conventional umbrella is composed of a frame (50) and a canopy (60) mounted on the frame (50).
The frame (50) has a shank (52) with a top end, a sliding ring (54), a spreader (542), a stretcher (56), a rib set (58) and a ferrule (522). The sliding ring (54) is movably mounted on the shank (52) and has an enlarged round top (not numbered), a telescoping tube (not numbered) extending from the round top and a stretcher base (544) mounted on the telescoping tube. The spreader (542) is composed of multiple rods (not numbered) pivotally and radially formed around the enlarged round top of the sliding ring (54) The stretcher (56) is also composed of multiple rods (not numbered) pivotally and radially attached around the stretcher base (544) The rib set (58) is composed of multiple rods pivotally and radially attached at the top end of the shank (52) to support the canopy (60) Each rod of the stretcher (56) movably connects one corresponding rod of the spreader (542) at a middle portion of the spreader rod and further has a distal end to pivotally connect to one corresponding rod of the rib set (58) Additionally, multiple retractable tabs (not shown) are formed on the shank (52) to selectively locate the sliding ring (54) at an extending position or at a retracting position.
Moreover, a limiting tube (70) is mounted on the shank (52) and secured under the top end of the shank (52) to selectively abut the stretcher base (544) of the sliding ring (54). Whereby, the limiting tube (70) enables the sliding ring (54) to stop in a preferred position to fully extend the stretcher (56) and keep the umbrella open.
However, the limiting tube (70) is usually made of rigid plastic and easily broken when the sliding ring (54) bumps against the limiting tube (70) whereby the umbrella malfunctions and must be thrown away. This is especially so when the umbrella is automatically extended by means of securing a restituting spring (not shown) around the telescoping tube of the sliding ring (54). The restituting spring is compressed and the telescoping tube retracts into the sliding ring (54) when the umbrella is at the retracting position. When the tab locating the sliding ring (54) retracts, the sliding ring (54) is released and rapidly bumps the limiting tube (70), causing vibrations and damage to joints of the frame (10).
With reference to FIG. 5, to avoid the vibrations and damage caused by bumping, a spring (80) is mounted on the shank (52) between the top end of the shank (52) and the stretcher base (544) of the sliding ring (54). Although the spring (80) provides a shock absorbing effect to the umbrella, it is difficult to secure the spring (80) under the top end of the shank (52) whereby the spring (80) slides along the shank (52) when the sliding ring (54) does not abut against the spring (80). However, the spring (80) sliding on the shank (52) is easily trapped by the multiple tabs emerging out from the shank (52) such that the operation of the umbrella blocked and inconvenient.
The present invention has arisen to provide a bumper for an umbrella to overcome and obviate the drawbacks of the conventional umbrellas.